2022-12-21 07:33:00

by Tianjia Zhang

Subject: [PATCH] crypto: arm64/sm4 - fix possible crash with CFI enabled

The SM4 CCM/GCM assembly functions for encryption and decryption is
called via indirect function calls. Therefore they need to use
SYM_TYPED_FUNC_START instead of SYM_FUNC_START to cause its type hash
to be emitted when the kernel is built with CONFIG_CFI_CLANG=y.
Otherwise, the code crashes with a CFI failure (if the compiler didn't
happen to optimize out the indirect call).

Fixes: 67fa3a7fdf80 ("crypto: arm64/sm4 - add CE implementation for CCM mode")
Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
Signed-off-by: Tianjia Zhang <[email protected]>
---
arch/arm64/crypto/sm4-ce-ccm-core.S | 5 +++--
arch/arm64/crypto/sm4-ce-gcm-core.S | 5 +++--
2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/crypto/sm4-ce-ccm-core.S b/arch/arm64/crypto/sm4-ce-ccm-core.S
index 028207c4afd0..fa85856f33ce 100644
--- a/arch/arm64/crypto/sm4-ce-ccm-core.S
+++ b/arch/arm64/crypto/sm4-ce-ccm-core.S
@@ -8,6 +8,7 @@
*/

#include <linux/linkage.h>
+#include <linux/cfi_types.h>
#include <asm/assembler.h>
#include "sm4-ce-asm.h"

@@ -104,7 +105,7 @@ SYM_FUNC_START(sm4_ce_ccm_final)
SYM_FUNC_END(sm4_ce_ccm_final)

.align 3
-SYM_FUNC_START(sm4_ce_ccm_enc)
+SYM_TYPED_FUNC_START(sm4_ce_ccm_enc)
/* input:
* x0: round key array, CTX
* x1: dst
@@ -216,7 +217,7 @@ SYM_FUNC_START(sm4_ce_ccm_enc)
SYM_FUNC_END(sm4_ce_ccm_enc)

.align 3
-SYM_FUNC_START(sm4_ce_ccm_dec)
+SYM_TYPED_FUNC_START(sm4_ce_ccm_dec)
/* input:
* x0: round key array, CTX
* x1: dst
diff --git a/arch/arm64/crypto/sm4-ce-gcm-core.S b/arch/arm64/crypto/sm4-ce-gcm-core.S
index 7aa3ec18a289..347f25d75727 100644
--- a/arch/arm64/crypto/sm4-ce-gcm-core.S
+++ b/arch/arm64/crypto/sm4-ce-gcm-core.S
@@ -9,6 +9,7 @@
*/

#include <linux/linkage.h>
+#include <linux/cfi_types.h>
#include <asm/assembler.h>
#include "sm4-ce-asm.h"

@@ -370,7 +371,7 @@ SYM_FUNC_START(pmull_ghash_update)
SYM_FUNC_END(pmull_ghash_update)

.align 3
-SYM_FUNC_START(sm4_ce_pmull_gcm_enc)
+SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_enc)
/* input:
* x0: round key array, CTX
* x1: dst
@@ -581,7 +582,7 @@ SYM_FUNC_END(sm4_ce_pmull_gcm_enc)
#define RH3 v20

.align 3
-SYM_FUNC_START(sm4_ce_pmull_gcm_dec)
+SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_dec)
/* input:
* x0: round key array, CTX
* x1: dst
--
2.24.3 (Apple Git-128)

2022-12-30 15:18:22

by Herbert Xu

Subject: Re: [PATCH] crypto: arm64/sm4 - fix possible crash with CFI enabled

On Wed, Dec 21, 2022 at 03:32:32PM +0800, Tianjia Zhang wrote:
> The SM4 CCM/GCM assembly functions for encryption and decryption is
> called via indirect function calls. Therefore they need to use
> SYM_TYPED_FUNC_START instead of SYM_FUNC_START to cause its type hash
> to be emitted when the kernel is built with CONFIG_CFI_CLANG=y.
> Otherwise, the code crashes with a CFI failure (if the compiler didn't
> happen to optimize out the indirect call).
>
> Fixes: 67fa3a7fdf80 ("crypto: arm64/sm4 - add CE implementation for CCM mode")
> Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
> Signed-off-by: Tianjia Zhang <[email protected]>
> ---
> arch/arm64/crypto/sm4-ce-ccm-core.S | 5 +++--
> arch/arm64/crypto/sm4-ce-gcm-core.S | 5 +++--
> 2 files changed, 6 insertions(+), 4 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt